ambassador susan rice will likely be the president's nominee to replace hillary clinton as secretary of state. on top of that, massachusetts senator john kerry is said to be the leading candidate to replace leon panetta at secretary of defense. >>> and we're also expected to learn this week whether the supreme court will take up a gay marriage case. at issue in the case is the defense of marriage act which states that marriage is between only one man and one woman. now, five federal courts have already ruled that act unconstitutional. the justices are expected to announce friday on whether they in fact will hear arguments in the case. >>> investigators now now what caused a massive explosion that ripped apart downtown springfield, massachusetts. the blast was triggered by a utility worker who punctured a natural gas line while investigating reports of a leak friday night. 18 people were hurt. most of those gas workers. police officers and firefighters. a sprip club was leveled and dozens of nearby buildings were badly damaged. >>> an inversion is now under way in new york after shred